Electric-arc lamp.



No. 667,120. Patented Jan. 29, 190i; R. FLEMING.

ELECTRIC ARC LAMP.

(Applicutioi fllod Nov. 9 1898.) (No Ilodl.) 2 Spats-Sheet l.

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No. 667,!20. Patented Jan. 29, I90l.

R. FLEMING.

ELECTRIC ARC LAMP.

(Appliction fllqd Nov. 9, 1898.) (In Model.)

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UNITED STATES PATENT OFFICE.

RICHARD FLEMING, OF LYNN, MASS ACHUSETTS, ASSIGNOR TO THE GENERAL ELECTRIC COMPANY, OF NEW YORK.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 667,120, dated January 29, 1901.

Application filed November 9, 1898. Serial No. 695,918. (No model.)

To all whom, it may concern:

Be it known that I, RICHARD FLEMING, a sub ect of the Queen of Great Britain, residing at Lynn, county of Essex, State of Mask sachusetts, have invented certain new and useful Improvements in Electric-Arc Lamps, (Case No. 787,) of which the following is a specification.

In electric-arc lamps as ordinarily constructed a magnet or magnets are employed to control the action of the feeding mechanism. This control in certain types of lamps is accomplished through the medium of a friction-clutch which acts either directly on the carbon or upon the carbon carrier or support, and as the carbons are consumed one or both are fed to compensate therefor and to maintain the are at the proper length. Under normal conditions the voltage across the are remains practically constant, differing, perhaps, by only a single volt between the time the carbons last fed and the time the clutch strikes the tripping-floor. If the tripping of the clutch ofiered no resistance to the action of the lamp, this would be satisfactory; but the clutch does not trip as soon as it strikes the floor, and it often happens that the voltage around the arc increases from ten to fifteen volts before the clutch will permit the carbons to feed. This is an objectionable feature; and one of the objects of my invention is to provide in a lamp having a frictionclutch for regulating the feeding of the carbons mechanism so arranged that the volrage at the arc will remain practically constant bot-h during the normal burning of the arc and the feeding of the carbons.

A further object of my invention is the improvement of the construction of arc-lamps, and to that end consists in the parts and combination of parts more fully described and claimed hereinafter.

In the accompanying drawings, which illustrate my invention, Figure 1 is a side view of an arc-lamp. Fig. 2 is a front view of the lampframe with the feed mechanism removed. Fig. 3 is a front elevation of the clutch. Fig. 4 is a section of the clutch,taken on the line t at of Fig. 3. Fig. 5 is an in- 56 closed detail view of the lamp-feeding mech- Fig. 6 is a detail of the moving conanism.

tact. Fig. 7 is a diagram of the circuit connections, and Fig. 8 is a detail view of the flange of the magnet-spool.

Referring more particularly to Figs. 1 and 2, A represents the main frame of the lamp, which consists of a rectangular body portion having a cylindrical head or base A, with upward extensions A forming a series of steps, the size of the frame decreasing as it extends 6o upward. The object of these steps is to permit the mounting of a suitable reactance when the lamp is intended for alternatingcurrent work or a resistance when the lamp is designed for constant high-potential circuits. By using a frame of this construction I am enabled to employ one type of frame for a variety of different lamps, thereby greatly reducing the cost of construction. Formed integral with the sides of the frame are flat 7o cylindrical lugs A which support a part of the feed mechanism and also serve as guides to hold the outer casing X (shown in dotted lines) in place. Mounted on top of the frame is an inverted-U-shaped metal plate B, having lugs B B extending outwardly therefrom, the said lugs extending parallel with the main body of the plate, but ata different level. Mounted on the lug B isa stationary binding-post O, which also acts as a terminal for the switch D. Mounted on the lug B is a binding-post D (shown only in diagram Fig. 7) and also a support for the switch D.

To prevent the plate from turning, a lug or projection 19 is formed thereon, which engages with a slot cut in the upper part of the frame A. The plate is secured in place by the hanger R, which is screw-threaded to the frame A. Mounted within the frame is a magnet-coil E. In the present instance this is 0 shown as consisting of two parts-a series coil E and a shunt-coil E differentially wound with respect to each other. Formed on the lower part of the frame are lugs A and on the top of the frame are similar lugs A E11- 5 gaging with these lugs are lugs c, formed'integral with the flanges or heads E of the magnet. (Best shown in Fig. 8.) The frame and magnet lugs are secured together by means of screws.

To remove the magnet E from the frame,

the hanger R is unscrewed, which permits the withdrawal of the carbon-tube G after the clutch has been removed therefrom. After removing the screws which secure the magnet to the frame the magnet, by disconnecting the winding, maybe removed from one side. It will be seen that only a very small amount of labor is required to take down and set up the lamp.

In addition to the magnets E E, I have provided a small shunt-wound magnet F, normally out of circuit, but which is included in circuit each time the carbon-tube G moves downward a certain amountand it is desired to feed the upper carbon. This magnet is supported from the top flange or head of mag net E by an extension E, which is formed integral with the lower head of the magnet spool. Secured to the upper end of the carbon-tube and insulated therefrom by mica or other insulating material G is a two-part frame H. To one end of this frame is secured a core II, arranged to work within a magnet F. On the other part of the frame is carried a contact-piece H having a silver tip for making good contact, which is arranged to make contact with the spring-pressed plunger I under normal operation and the cut-out con tact I when for any reason the lamp fails to operate, due to sticking of the carbons or to their being entirely consumed. The portion of the frame which carries the contact H is slotted, and between the contact and the sides of the frame are sheets of insulating material it. In the present instance mica has been employed; but any other form of insulating material may be used, if desired.

In Fig. (3 is shown a detailed construction of the spring-pressed contact-I. This contact is mounted in a plate 1 having a tubular extension I", containing the spring I and under normal conditions the plunger is in the position shown, the pin 2' preventing it from being removed. The contacts I I are insulated from each other by means of mica or other insulating material I The cut-out contact I and the plate I are mounted on an inverted- U-shaped support 1 the extensions of which rest on the lugs A of the frame A. To prevent the too-rapid movement of the frame H, a dash-pot J is employed, the piston being carried by the frame H and the cylinder by a fixed portion of the lamp. Situated at one side of the dash-pot is an adj ustableextension-springK. (llloreclearlyshown in Fig. 5.) This spring is arranged to compensate for the weight of the moving parts.

Extending parallel with the magnets E and E in a vertical direction is a frame L, upon which is wound a starting resistancewire L, which is normally out of circuit, but is cutin at the time the movingcontactH strikes the stationary contact 1.

Situated below the frame-head A is a similar frame-head A, and between these heads is a layer of asbestos or other heat-resisting material A The object of this material is to prevent the passage upward through the lamp mechanism of the heat generated by the are.

Extending downwardly from the head A are two side tubes S, which support the lowercarbon holder S, and mounted for vertical movement within these tubes are rods T, which carry the globe-holder T.

Mounted on the lower end of the carbon tube G is a floating clutch, so called because it floats up and down with the armature and carbon-tube. This clutch is best shown in Figs. 3 and 4-, and consists of a collar M, which is clamped to the carbon-tube by a screw M. Formed integral with and extending downwardly from the collar are four arms M These are best shown in Fig. 4. The arms on opposite sides of the carbon N are connected by the horizontally-extending pieces M These pieces serve to make the arms of the clutch more rigid and at the same time act as stops for limiting the downward movement of the shoes H". Ti shoes M" are mounted eecentrically, so that they tend to grip the upper carbon N when the tube G is raised, and by reason of their being pivoted at a considerable distance from the carbon are very sensitive and the effort required to release the carbon is very small. At the same time the carbons are held very firmly and prevented from dropping down due to jarring. Mounted in the shoes are pins M, which extend on both sides thereof and are adapted to engage with the side pieces M of the frame to limit the downward movement of the shoes. It will be seen that the construction of this clutch is very simple, and that the machine-work required amounts to very little. The only portions of the clutch requiring machine-work are the collar b1, the holes in the frame and shoes for the reception of the pivots M and the pins M and the gripping-surfaces of the shoes M", which are cut in such a manner that they present surfaces curved concentric with the carbon.

The adjustment of the lamp is very simple. The contact H of the feed-magnet F is first adjusted to the proper distance from the contact I. Then the clutch is moved up or down on the carbon-tube until the shoes M are so disposed that they will when gripping a carbon strike the tripping-floor M at or about the time the contacts [I and I close. It is preferable to adjust the parts so that the contacts close just ahead of the striking of the clutch-shoes, for by this arrangement there is no opportunity for the arc voltage to increase above normal,

In Fig. '7 is shown a diagram of the circuit connections, in which C and D represent the binding posts, and D the short -circuiting switch. The series coil E is connected between the binding-posts D and the lower carbon N. The shunt-coil E is connected between the binding-post D and the bindingpost C. One end of the starting resistance L is connected to the fixed contact I and the other end is connected to the binding-postD.

Extending from the binding-post O is a connection O, which is connected to the moving contact H and also to the carbon-tube Gand upper carbon N. When the lamp is operating under normal conditions, the parts will be as shown, and as the carbons are consumed the carbon-tube and clutch will gradually be lowered, due to the changes of strength in magnets E E until the shoes M of the clutch are on the point of engaging with the tripping-platform M At or about this instant the contact H carried by the frame H, will move downward and strike the spring-pressed contact I. At the instant the circuit is closed at this point current will flow from one binding-post to the other, which will energize the magnet F and cause it to attract its core H. This will force the clutch-shoes M against the tripping-platform M with a slight blow and cause them to release the carbon N and permit it to feed.

I have experimented with a lamp of the character shown, as well as with other lamps,

and have found that when the magnet F is rendered inoperative the clutch and carbontube will feed downward as the carbons are consumed and the voltage at the arc will remain practically constant, varying when the lamp parts are carefully adjusted not over one volt up to the time that the jaws of the clutch strike the tripping-platform; but as soon as this is done the voltage at the arc may increase from ten to fifteen volts before the effect is enough to cause the shoes to release the carbon and permit it to feed. On the other hand, I have found that to place the coil F in circuit, as shown, and to include it in circuit at or about the instant the shoes M strike the tripping-platform will cause the carbons to feed without changing the voltage at the are more than from one to three volts. This variation in voltage is due largely to inequalities in the carbon and to the sticking of the various parts; but it will be readily seen that the advantage gained is very marked.

It will be seen that while I have provided the so-called drop-feed for feeding the carbons, the ordinary feed mechanism of the lamp has still been retained, and in the event of the failure of the drop-feed to operate from any cause the lamp is not rendered inoperarive, which is a very important feature where the lamp is employed for street service and where the aim is to keep the lamp going at any cost.

\Vhat I claim as new, and desire to secure by Letters Patent of the United States, is-

1. In an electric-arc lamp, the combination of a magnet, a floating friction-clutch for regulating the feeding of the carbons,which clutch under normal conditions is supported and controlled by the magnet, and a normally opencircuited magnet which is energized each time the clutch is tripped for assisting the release of the clutch.

2. In an electric'arc lamp, the combination of a differentially-wound magnet for striking arcs and actuating the feed mechanism, with an auxiliary magnet acting on the feed mechanism to assist in releasing the clutch, the auxiliary magnet being normally open-circuited but placed in a circuit at or about the instant the clutch should release.

3. In an electric-arc lamp, the combination of an arc-regulating solenoid, a core for the solenoid, a floating friction-clutch carried by the core, the clutch, core and solenoid being so arranged that they are capable of feeding the carbon, a normally open-circuited magnet which comes into action at or about each time the arc reaches a determined length, and contacts for closing the circuit of the second magnet.

4. In an electric-arc lamp, the combination of a floating friction-clutch for regulating the feeding of the carbons, means for tripping the clutch, a magnet for controlling the clutch which is capable of causing the carbon to feed, and a second magnet which is normally out of circuit during the operation of the lamp, but which is energized at or about the instant the clutch strikes the tripping means,for causing a quick release of the clutch.

5. In an electric-arc lamp, the combination of a floating clutch, a magnet for raising and lowering the clutch, a tripping means for the clutch, an auxiliary magnet, normally inactive, for causing the clutch to strike the tripping means with a slight blow each time the carbon should feed in order to give a quick release to the carbon, and a moving and a stationary contact for closing the circuit of the auxiliary magnet.

6. In an electric-arc lamp, the combination of a series and a shunt coil differentially acting, a floating friction-clutch governed thereby, the clutch and coils being capable of feeding the carbon, and a shunt-magnet normally open-circuited, but acting to give a sudden downward movement to the clutch each time it should feed, and contacts for closing the circuit of the shunt-magnet.

7. In an electric-arc lamp, the combination of a magnet acting on aclutch to regulate the feed of the carbons, a clutch, a normally open-circuited winding, arranged when energized to give a sudden downward movement to the clutch at the instant it should feed, a resistance, and contacts for first closing the circuit of the said winding and then closing the circuit of the resistance.

8. In an electric-arc lamp, the combination of a tube surrounding the carbon, a clutch carried by the tube and arranged to grip the carbon, a magnet for raising and lowering the tube as the potential across the arc varies, an auxiliary magnet normally open-circuited, an armature for the magnet, which is connected to the tube, and a contact carried by the tube for closing the circuit of the auxiliary magnet so as to impart a quick movement to the tube and clutch each time the carbon should feed.

9. In an electric-arc lamp, the combination ITO of a carbon, a tube surrounding the carbon, a clutch mounted on the tube, a feed-magnet, a drop-feed magnet normally open-circuited, a core therefor, a frame mounted on the tube which carries the core, and a contact for closing the circuit of the magnet each time the carbon should feed.

1.0. In an electric-arc lamp, the combination of a carbon -surrounding tube, a two-part frame carried bythe tube and insulated therefrom, a magnet-core carried by one part of the frame, and a contact carried by the other part of the frame and an arc-regulating coil cooperating with the core and controlled by the contact.

11. As an article of manufacture, a contact for an electric lamp comprising an inverted- U shaped bridge or support carrying a springpressed contact mounted within a tubular support, and a Hat contact which is insulated from the spring-pressed contact.

12. As an article of manufacture, the frame for an electrie-arc lamp, comprising a rectangular body having a cylindrical base or head forming one end, and a portion provided with a series of steps forming the other end, lugs formed on the side of the frame which serve to hold the outer casing in position when mounted on the frame, and tubes extending downwardly from the cylindrical head and arranged to support the lower-carbon holder.

13. As an article of manufacture, a clutch for an electric-arc lamp comprising a collar M, pairs of downwardlyextending arms M formed integral therewith, side pieces M extending around the carbon and connecting the corresponding arms on the same side of the center, and pivoted eccentric clutch-shoes located between the arms.

14. In a clutch for an are-lamp, a clutchframe mounted upon and movable with the carbon-holder, rigid depending arms transversely connected at their lower ends carried by the collar, clutch -jaws pivoted in the arms, and stops to limit the descent of the jaws by engagement with the frame.

15. In an electric-arc lamp, the combination of a normally open-circuite ;l feed-magnet, a starting resistance normally open-cireuited, and means for closing one of said open circuits in advance of the other.

1t. In an electric-arc lamp, the combination of a normally open-circuited magnet, a resistance also normally open-circuited and means for closing the circuit of the magnet first and of the resistance afterward.

In testimony whereof I have hereunto set my hand this 7th day of November, 1898.

RICHARD FLEMING.

Witnesses:

W. DH. RYAN, D. MOKILLO'P. 

